Alan bought a spirit level because the shelf in his kitchen kept tilting.
The next morning he returned it. “This one’s broken. It says my shelf, counter and floor are all crooked.”
The shopkeeper tested it on his counter. The bubble sat in the middle. He tested it on the window ledge. Same result.
Alan folded his arms. “Then why does it show three different problems in my kitchen?”
“Because it’s a very good level,” the shopkeeper said. “You’ve brought me the only straight thing from that room.”